1 /* @(#)e_remainder.c 5.1 93/09/24 */
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
6 * Developed at SunPro, a Sun Microsystems, Inc. business.
7 * Permission to use, copy, modify, and distribute this
8 * software is freely granted, provided that this notice
10 * ====================================================
12 * $NetBSD: e_remainder.c,v 1.11 2002/05/26 22:01:52 wiz Exp $
13 * $DragonFly: src/lib/libm/src/e_remainder.c,v 1.1 2005/07/26 21:15:20 joerg Exp $
18 * returns x REM p = x - [x/p]*p as if in infinite
19 * precise arithmetic, where [x/p] is the (infinite bit)
20 * integer nearest x/p (in half way case choose the even one).
22 * Based on fmod() return x-[x/p]chopped*p exactlp.
26 #include "math_private.h"
28 static const double zero
= 0.0;
32 remainder(double x
, double p
)
38 EXTRACT_WORDS(hx
,lx
,x
);
39 EXTRACT_WORDS(hp
,lp
,p
);
44 /* purge off exception values */
45 if((hp
|lp
)==0) return (x
*p
)/(x
*p
); /* p = 0 */
46 if((hx
>=0x7ff00000)|| /* x not finite */
47 ((hp
>=0x7ff00000)&& /* p is NaN */
48 (((hp
-0x7ff00000)|lp
)!=0)))
52 if (hp
<=0x7fdfffff) x
= fmod(x
,p
+p
); /* now x < 2p */
53 if (((hx
-hp
)|(lx
-lp
))==0) return zero
*x
;
69 SET_HIGH_WORD(x
,hx
^sx
);